Which term describes a lack of genetic diversity due to physical barriers?

The term that describes a lack of genetic diversity due to physical barriers is geographical isolation. This concept refers to the separation of populations by physical barriers such as mountains, rivers, or distances that prevent interbreeding. When a population becomes geographically isolated, the gene flow between it and other populations is restricted, which can lead to reduced genetic variation over time. This can have significant impacts on the evolutionary trajectory of the isolated population, making it more vulnerable to environmental changes, diseases, and reducing its ability to adapt.

In contrast, ecosystem collapse refers to a breakdown of an entire ecosystem often due to various stress factors, while a population bottleneck describes a significant reduction in population size due to environmental events or human activities, which can lead to decreased genetic diversity. Cultural isolation pertains to social or behavioral aspects of societies and does not address the genetic consequences of physical barriers.